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/HTTP

Accept

Accept

The Accept request HTTP header indicates which content types, expressed as MIME types, the client is able to understand. The server uses content negotiation to select one of the proposals and informs the client of the choice with the Content-Type response header. Browsers set required values for this header based on the context of the request. For example, a browser uses different values in a request when fetching a CSS stylesheet, image, video, or a script.

Header type Request header
Forbidden header name no
CORS-safelisted request header yes, with the additional restriction that values can't contain a CORS-unsafe request header byte: 0x00-0x1F (except 0x09 (HT)), "():<>?@[\]{}, and 0x7F (DEL).

Syntax

Accept: <MIME_type>/<MIME_subtype>
Accept: <MIME_type>/*
Accept: */*

// Multiple types, weighted with the quality value syntax:
Accept: text/html, application/xhtml+xml, application/xml;q=0.9, image/webp, */*;q=0.8

Directives

<MIME_type>/<MIME_subtype>

A single, precise MIME type, like text/html.

<MIME_type>/*

A MIME type, but without a subtype. image/* corresponds to image/png, image/svg, image/gif, and other image types.

*/*

Any MIME type

;q= (q-factor weighting)

A value used is placed in an order of preference expressed using a relative quality value called the weight.

Examples

Accept: text/html

Accept: image/*

// General default
Accept: */*

// Default for navigation requests
Accept: text/html, application/xhtml+xml, application/xml;q=0.9, */*;q=0.8

Specifications

Specification
HTTP Semantics
# field.accept

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
Accept
Yes
12
Yes
In Firefox 66, the default Accept header value changed to */*.
Yes
Yes
Yes
Yes
Yes
Yes
In Firefox 66, the default Accept header value changed to */*.
Yes
Yes
Yes

See also

© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Accept